FIG. 10 shows an example of a lighting circuit of a conventional organic electroluminescence (electroluminescence) lamp. The conventional lighting circuit supplies a DC power source 11 to an organic electroluminescence lamp 15 by a lamp current control circuit 18. A switch Tr1 (12) is controlled based on the comparison result so that a lamp current Ila detected as a voltage value by a resistor R1 (14) and an Ila reference value set in an Ila reference value setting unit 17 preset so as to supply a rated current to the lamp become equal.
The lamp current Ila, the lamp (module) temperature, and lamp voltage Vla become as shown in FIG. 11. FIG. 11 shows change in the lamp current Ila, the lamp (module) temperature, and the lamp voltage Vla at the transient time from lighting start time 0 to time t1 and at the later stationary time (for example, refer to Patent Document 1).
Patent Document 1: Japanese Patent Publication No. 2007-122981